The present invention relates to a solid-state image sensor, a solid-state image sensing device, and a method of producing the same, and in particular, to a CCD solid-state image sensor, a CCD solid-state image sensing device, and a method of producing the same.
A conventional solid-state image sensor used in a video camera or the like, in which light sensing elements are arranged in matrix form, includes, between light sensing element lines, a vertical charge coupled device (Vertical CCD: Charge Coupled Device) for reading signal charges generated by the light sensing element lines.
A structure of the aforementioned conventional solid-state image sensor will be described in the following (refer to, for example, Patent Document 1). FIG. 1 is a sectional view showing a unit pixel of the conventional solid state-image sensor. A photodiode (PD) are composed of an n-type photoelectric conversion region 13 which is formed in a p-type well region 12 formed on an n-type substrate 11 and functions as a charge storage layer, and a p+-type region 14 formed on the n-type photoelectric conversion region 13.
An n-type CCD channel region 16 is formed in the p-type well region 12 as an n-type impurity region. There is provided a read channel formed by a p-type impurity region between the n-type CCD channel region 16 and the photodiode on the side of reading the signal charge to the n-type CCD channel region 16. The signal charge generated in the photodiode is read through the read channel after being temporarily stored in the n-type photoelectric conversion region 13.
There is provided a p+-type isolation region 15 between the n-type CCD channel region 16 and other photodiodes. By the p+-type isolation region 15, the photodiodes and the n-type CCD channel region 16 are isolated, and respective n-type CCD channels 16 also are isolated not to touch with each other.
A transfer electrode 18 is formed on a surface of the semiconductor substrate via a Si oxide film 17, which horizontally extends so as to pass through between the photodiodes. Incidentally, the signal charge generated in the photodiode is read to the n-type CCD channel region 16 through a read channel below a transfer electrode to which a read signal is applied among the transfer electrodes 18.
A metal shield film 20 is formed on the surface of the semiconductor substrate in which the transfer electrode 18 is formed. The metal shield film 20 includes a metal shield film opening 24 for every photodiode as a light transmitting portion which transmits the light received by the p+-type region 14 acting as a light receiving portion.
Patent Document 1; Japanese Unexamined Patent Publication (Kokai) No. 2000-101056